First of all, are you flying QF (as I see above, this thread has been moved here from the QF forum) or CX (LHR-HKG-AKL)?

Foreign currency (apart from the Renmenbi/Chinese yuan at some locations) is not accepted in Hong Kong.

A list of restaurants/shops can be found here: http://www.hongkongairport.com/eng/s...ll/dining.html . Try Tsui Wah Eatery if you want some good Chinese/Asian food. If you're only after some refreshments (drinks, etc.), you can buy a la carte at Burger King or McDonald's.

You could also consider donating some of your excess change (HKD) to UNICEF's Change For Good (as said above) if flying CX or using it for onboard duty free.